All false, according to Snopes.com, a Web site devoted to finding the truth (or lack thereof) behind urban legends, rumors, gossip and other forms of hearsay. Thanks to the snoops at Snopes, we know that Coca-Cola is not an effective spermicide, mixing a pregnant woman’s urine with Drano does not reveal the gender of her unborn child and the Make-A-Wish Foundation will not donate 7 cents for the medical care of dying children every time you or someone in your address book forwards them a copy of the e-mail that spawned this fiction.

Snopes hasn’t weighed in on whether Michelle Obama was captured on videotape spewing off about “whitey,” a story that has been making the rounds for weeks despite no sign of an actual video. But her husband, the presumptive Democratic nominee for president, has set up his own truth-squad site, fightthesmears.com, to counter such claims.

Barack Obama and John McCain have the personal integrity to make this a tremendously uplifting presidential campaign. But a lot of other people seem to have something else in mind.

Perhaps a copy of “50 Lies Told By Barack Obama” has already hit your inbox. Maybe you’ve read that the Ku Klux Klan has endorsed Obama or that his erstwhile opponent, Sen. Hillary Clinton, refused to meet with members of the Gold Star Mothers, whose sons were killed in combat. In 2000, George W. Bush supposedly refused to sell his Dallas home to blacks.

Again, all false. And probably not by accident.

Back when misinformation was spread by word of mouth, half- truths often fizzled before causing much harm. Now, though, they can rocket around the globe in the time it takes to hit the “forward” button. That’s much less time than it takes to reflect on whether they’re true or fair.

That’s why a story about Satanists using the Harry Potter books to recruit new members can take on a life of its own before someone points out that it originated in The Onion. It’s why the U.S. Postal Service still gets angry messages about a fictional bill in Congress that would levy a 5-cent charge on every e-mail and why many Americans think they have to call a toll-free number and “opt out” to prevent credit bureaus from selling their financial information. Don’t believe it.